Japanese voice actor: Tatsuya Kando (CoM), Nachi Nozawa (Re:CoM)
English voice actor: Tatsuya Kando (CoM), Derek Stephen Prince (Re:CoM)
Vexen (ヴィクセン ,Vikusen?) is a scientist who is also known as the "Chilly Academic" (いてつく学究 ,Itetsuku Gakkyū?) and full of pride, looking down on those lower then him in the Organization's hierarchy. Vexen's original self was Even (エヴェン ?), and he was interested in studying Xehanort's memories. Vexen can control ice and carries a large kite shield in battle that blocks any frontal attacks made against him or use as a medium to generate a blade of ice.
In Chain of Memories, Vexen sides with Zexion and Lexaeus, other members occupying the castle's basements, to prevent Marluxia's plan to overthrow the Organization. He first battles Riku in order to gather data to create a replica of him. Once he creates the replica Riku, Vexen is assigned to investigate Marluxia's intentions after he tested his creation against Riku. However, Vexen cares nothing for his "experiment" and allows Naminé to manipulate the Riku Replica's memories against his wishes in order to test Sora's worth to the Organization. When the Replica fails to defeat Sora, Marluxia threatens to reveal the shortcoming to Xemnas, forcing Vexen to take on Sora himself with intent to kill the boy. Introducing himself to Sora, Vexen says that he came to collect his "debt" and provokes Sora into fighting him by making him believe that he controlled Riku rather than created a replica.
After their battle, Vexen gives Sora the card to Twilight Town with the intention of revealing Roxas's existence. Marluxia considers him a traitor as a result and sends Axel to kill him. In Twilight Town, Vexen attempts to reveal to Sora why he feels as though he has been to Twilight Town despite being fairly certain that he had never been there. Sora and Vexen battle again after Vexen tells Sora that if he can not listen to his heart, he has no right to exist. After being defeated, Vexen is killed by Axel as he is about to reveal Marluxia's plot. (In the original Chain of Memories, Axel cuts Vexen down with his chakrams, while he is incinerated in Re:Chain of Memories.)
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